Notice: Undefined variable even if i have @ before

Keywords´╝Ü php laravel

Question: 

Normally in php 5.6 i was checking like this if a variable exists if(@!$isIssue) { } without producting any error of course.

Now in php 7.3 and more specifically in Laravel 5.8 the code if(@!$isIssue) {} produces ErrorException Undefined variable.

Since a lot of code is written with @ instead of if(isset($isIssue)) I was wondering if anyone knows whats the issue and it stopped working.

Answers: